diff --git a/package.json b/package.json
index 200222d..a986e31 100644
--- a/package.json
+++ b/package.json
@@ -27,7 +27,7 @@
   "homepage": "https://github.com/cybertk/ramlev",
   "dependencies": {
     "async": "^2.0.1",
-    "chai": "~3.5.0",
+    "chai": "~4.0.0",
     "coffee-script": "~1.12.3",
     "csonschema": "^0.5.1",
     "mocha": "^2.2.5",